Furnace for metallurgical processing

ABSTRACT

A furnace for metallurgical processing comprises a ring mounted for tilting on a horizontal axis extending diametrically of the ring, and a vessel for holding a charge to be processed mounted in the ring for rotation relative thereto on an axis generally perpendicular to the plane of the ring. The ring and vessel are journaled to accommodate axial thrust forces and radially directed thrust forces therebetween, and moments of such forces. Connecting pins are provided for supporting and driving engagement between the ring and vessel, the pins also functioning to accommodate thermal expansion of said vessel.

United States Patent 1 Alexander et al.

Oct. 1, 1974 [54] ggggfgg fig METALLURGICAL FOREIGN PATENTS OR APPLICATIONS 987,282 3/1965 Great Britain 266/36 P [75] Inventors: Alex F. Alexander, Essen, Germany; 888,813 2/1962 Great Britain 266/36 H Ludovicus M. Dierckx; Alphonse S. J. Van Raevels, both of Beerse, Primary Examiner-Gerald A. Dost Belgium Attorney, Agent, or Firm-Koenig, Senniger, Powers and Leavitt [73] Assignee. La Metallo-Chlmique S.A., Brussels,

Belgium [57] ABSTRACT [22] June 1973 A furnace for metallurgical processing comprises a [21 Appl. No.: 371,973 ring mounted for tilting on a horizontal axis extending diametrically of the ring, and a vessel for holding a charge to be processed mounted in the ring for rotation relative thereto on an axis generally perpendicw Hr to the plane of the ring The ring and Vessel are [58] new of Search 266/35 36 36 75/76 journaled to accommodate axial thrust forces and ra- 56 R f Ct d dially directed thrust forces therebetween, and mo- L 1 e erences 1e ments of such forces. Connecting pins are provided UNITED STATES PATENTS for supporting and driving engagement between the 3,163,696 12/1964 Johansson et al. 266/36 P ring and vessel, the pins also functioning to accommo- 3,169,755 2/1965 Eklund et al. 266/36 P X date thermal expansion of said vessel, 3,201,108 8/1965 Kramer 266/36 P 3,682,623 8/1972 Dierckx 6161. 75/76 23 Clalms, 7 Drawmg Figures 9 h??? l 37 /55 Z51;

25 7,2," l "I rm i 22 1 1 5 4 r/ 5 25 2r 7f, #73 L i {7/2 0 o o 55 m;

/3 4/ 2;; i i i 1 1 11Ir/l l ////,j, 43 47 47 j if! 3 33 L n A It? 7 Z/ FURNACE FOR METALLURGICAL PROCESSING BACKGROUND OF THE INVENTION This invention relates to metallurgical furnaces, and more particularly to a rotary furnace of this class.

The invention is particularly concerned with a rotary furnace of the type shown in the coassigned US. Pat. No. 3,682,623 of Ludovicus Maria Dierckx, Denis Lucian Feron and Karel Guns, for carrying out metallurgical processes, especially for recovery of copper from copper-bearing materials, though not limited to copper recovery. The furnace shown in said US. Pat. No. 3,682,623 is of a type having a vessel for containing a charge to be processed rotatable in a ring, the ring being swingable on a horizontal axis to tilt the vessel. A furnace of this type which has been used in commercial production is one in which the vessel has been driven via a friction drive including a friction drive roller engaging in a peripheral groove in a ring surrounding and secured to the vessel. This furnace cannot be operated, as a practical matter, with the vessel at an angle of greater than about 20 to the horizontal. It has been found desirable, however, to operate the tilt-ring rotary-vessel type of furnace with the vessel at a relatively high angle to the horizontal (greater than 20 and on up to close to vertical) to effect a considerable saving or reduction in the driving torque applied to the vessel without losing mixing power or agitation of the charge in the vessel, also to reduce pollution via utilization of the updraft force of exhausting gases at the higher angles, and further to enable holding a larger charge in the vessel (the higher the angle of the vessel, the greater its capacity.) These prior rotary furnaces have had certain movable parts on the outside of the vessel subject to having materials fall into them when the vessel is being charged, and have been of such construction as to require turning the vessel to inverted vertical position for certain maintenance operations (e.g., changing bearings), and consequent substantial down time. They have also had the problems of such vibration of the vessel as to cause undesirably rapid deterioration of the refractory lining of the vessel, and of interference with free spinning of the vessel on account of thermal expansion problems resulting from undue rise in temperature of the charge in the vessel.

SUMMARY OF THE INVENTION Among the several objects of the invention may be noted the provision of a rotary furnace of the class described adapted for rotation of the vessel with the axis of the vessel at any angle to the horizontal, and particularly at much greater angles to the horizontal than possible with prior furnaces (e.g., close to vertical), for re ducing the driving torque required to rotate the vessel without loss of agitation of the charge in the vessel, for reducing pollution, and for holding a larger charge in the vessel; the provision of such a furnace which does not have any movable parts on the outside of the vessel prone to be clogged by materials spilling over when the vessel is being charged, and which is adapted for maintenance (c.g., changing bearings) in an upright or tilted position, thereby avoiding undue down time for maintenance operations since they may be carried out without inverting the vessel; the provision of such a furnace wherein vibration of the vessel is reduced to the extent that the refractory lining of the vessel has a substan- 2 tially longer life, and a thinner working lining may be used; and the provision ofa construction for a furnace such as described adapted to maintain the vessel spinning freely despite undue rise in temperature of the charge in the furnace.

In general, a furnace of this invention comprises a ring, means supporting the ring for the tilting thereof on a generally horizontal axis extending diametrically of said ring, a vessel for holding a charge to be processed, means mounting the vessel in said ring for rotation on an axis generally normal to the plane of said ring and extending generally centrally of said ring. and means for rotatably driving said vessel relative to said ring. The mounting means comprises a first annular bearing means secured to said ring, a second annular bearing means secured to said vessel surrounding the latter, a set of radial thrust bearings interposed between said first and second annular bearing means, and at least one set of axial thrust bearings interposed between said first and second annular bearing means for bearing the load of said vessel. Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of a furnace embodying the present invention, with parts broken away and shown in section, showing the vessel of the furnace in a generally vertical position;

FIG. 2 is a left side elevation of the furnace, showing the vessel in a tilted position;

FIG. 3 is a plan of FIG. 1;

FIG. 4 is an enlarged fragment of FIG. 1;

FIG. 5 is a section on a larger scale than FIG. 4, showing a detail;

FIG. 6 is a diagrammatic view showing an alternative type of drive for the vessel; and I FIG. 7 is a view showing a modification.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT of this invention comprising a vessel 3 having a cylin drical sidewall 5, a generally circular bottom or lower end 7, and a frustoconical upper end 9 open at the top to provide an open mouth 11. The vessel 3 comprises a steel shell 13 having a refractory lining 15 therein, the latter usually comprising a so-called working lining on the inside of an outer insulation lining. A cooling shell 17 is provided for the lower part of the vessel, spaced outward of the lower end of the cylindrical sidewall 5 and bottom 7 of the vessel. The space between the ves sel and the shell 17, indicated generally at 19, is provided for flow of air down around the vessel, the shield having a bottom opening 20 for exit of air. A nut 21 is provided at the center of the bottom 7 of the vessel for securement of an eyebolt (not shown) used to suspend the vessel in inverted position. The vessel may have a suitable bottom tap hole (not shown). The vessel 3 is rotatable about its cylindrical axis within a ring 23 mounted for swinging movement about a horizontal axis extending substantially diametrically of the ring so that the vessel may be pivoted between an upright position and a tilted position, as discussed hereinafter. The ring 23 is provided with diametrically oppositely extending trunnions 25, 27, with the trunnion 25 journaled in a bearing 29 on a pedestal 31 on a footing 33 and the other trunnion keyed in the hub 35 of a rela tively large wheel gear 37. The wheel gear 37 is mounted for rotation on a horizontal axis and cradled in two cradling rollers 39, 41 while meshing with a drive gear 43, said rollers and drive gear each being journaled in bearing assemblies 45, 47 and 49 provided on a support 51 on a footing 53. The drive gear 43 is adapted to be driven by any suitable drive means, such as an electric (or hydraulic) motorspeed reducer drive (not shown), and the driving gear 43 drivingly rotates the wheel gear 37 to swing the ring 23 about the horizontal axis of said gear wheel and the trunnions 25, 27.

As shown more particularly in FIG. 4, a housing 55 secured to the wheel gear 37 for concerted movement therewith carries a power drive unit 57, e.g., a hydraulie (or electric) motor, for driving the vessel 3 in any attitude thereof. The output shaft of unit 57 carries a gear 59 in mesh with a pinion 61 for driving the vessel. At 63 is indicated an electric brake of a well-known conventional type for holding the shaft 65 of the pinion 61 against rotation to hold the vessel against rotation.

For mounting the vessel 3 in the ring 23 for rotation therein, as shown in FIG. 5, an annular ring member 67 is provided depending from the bottom of the ring secured to the latter by a plurality of machine screws 69. An annular flange 71 is integrally formed on the ring member 67 extending generally radially outwardly therefrom spaced down from the bottom of ring 23, the peripheral edge or circumferential surface of this flange defining a cylindric bearing surface 73. The annular upper and lower flat sides or faces of flange 71 define oppositely facing upper and lower bearing surfaces 75, 77 which are substantially normal to the peripheral bearing surface 73. Other annular members 79, 81 and 83 are assembled in face-to-face abutting engagement with each other by suitable means, such as a plurality of machine screws 85. The cooling shell 17 is secured to the lower annular member 79 of this assembly by means such as indicated at 87, and rotates with member 79 (and with the vessel). The upper and intermediate annular members 81, 83 surround the annular ring member 67. The upper annular member 81 is provided with an annular flange 89 extending radially inwardly between the bottom of the ring 23 and the upper bearing surface of flange 71 on ring member 67. The inner edge of flange 89 closely surrounds the upper portion of ring member 67 above flange 71 and flange 89 has a downwardly facing annular bearing surface 91 in axially spaced relation with the opposing upper annular bearing surface 75 of flange 71. An inwardly facing annular cylindrical bearing surface 93 is provided on the upper annular member 81 and spaced radially outwardly from the opposing peripheral bearing surface 73 offlange 71. An upwardly facing annular bearing surface 95 is provided on the intermediate annular member 83 in opposed axially spaced relation to the lower bearing surface 77 of flange 71. Upper and lower sets of axial thrust bearings 97, 99 are journaled between the upper and lower bearing surfaces 75, 77 on the ring flange and the upper and lower bearing surfaces 91, 95 on the upper and intermediate annular members 81, 83, respectively, and a set of radial thrust bearings 101 is provided in journaling engagement between the opposed thrust bearing surfaces 73, 93 on the ring member flange 71 and the upper annular member 81, respectively. The upper annular member 81 is formed as a ring gear 103 at its outer periphery, and connected in driven engagement through the idler gear 61 with the driving gear 59 (see FIG. 4).

The annular member 79 is formed with a plurality of radially extendingbosses 105 having inner end portions projecting through openings 107 (see FIG. 5) provided therefor in the shield 17 into space 19 between the shield and the shell 13 of vessel 3. Bosses 105 are spaced at equal intervals around member 79, each having a radial bore or hole 109 therein (radial with respect to the axis of the vessel 3). Bores 109 are coaxially aligned with bores 111 in a plurality of tubular socket members 113 secured at spaced intervals around shell 13 (the same intervals as the bosses 105) as by welding at 115. Pins 117, secured in the bores 111 of the bosses as by set screws 118, extend radially inwardly from the bosses into the bores 111 in sockets 113, having a sliding fit in the latter, and thus functioning to support the vessel and provide driving connections between member 79 and the vessel while permitting thermal expansion and contraction of the shell 13 of vessel 3 within member 79.

It will be observed that the vessel 3 thus has means mounting it for rotation in the tilt ring 23 for rotation on an axis generally normal to the plane of the ring 23 and extending generally centrally of the ring 23, this means comprising the member 67 functioning as a first annular bearing means secured to the bottom of ring 23 and the assembly of members 79, 81 and 83 secured to the vessel 3 surrounding the latter, functioning as a second annular bearing means, with the set of radial thrust bearings 101 interposed between the said first bearing means 67 and the said second bearing means 79, 81, 83 and the sets of upper and lower axial thrust bearings 97 and 99 also interposed between the said first and second bearing means, with bearings 97 generally bearing the load of the vessel. Member 81 of means 79, 81 and 83 comprises the ring gear 103 in the drive train from power drive unit 57 for rotating means 79, 81 and 83 and thereby rotating the vessel 3 within the ring 23 via the pin connections 117 between means 79, 81 and 83 and the vessel. With the pins 117 fixed in the outboard bores 109 and having their inner ends slidably received in the inboard bores 111 of sockets 113 on the vessel, the vessel is free thermally to expand within member 79, at least within predetermined limits.

An annular air duct 161 surrounds the vessel 3 on top of the ring 23. At 163 is indicated a blower carried by the gear wheel 37 for supplying air to this duct. A frusto-conical cooling shell 165 surrounds the frustoconical upper end 9 of the vessel 3 above the ring 23, this shell being spaced from the upper end 9 of the vessel, with the space 167 between the upper end of the vessel and shell 165 in communication with the duct 161 as indicated at 169 for flow of air upwardly in the space 167 to cool the upper end of the vessel, the air exiting at 171. The duct is secured to the ring 23 and the shell 165 is secured to the duct so that neither the duct nor the shell rotates with the vessel 3. A cylindrical cooling shell 173 surrounds the vessel between the duct and the shield 17, being secured on the inside of the ring 23 with suitable spacers 175 (see FIG. 5) be tween the inside of the ring 23 and the shell. The duct 161 is open at the bottom as indicated at 177 for flow of air downwardly in the space 179 between the shell and the vessel to the space 19 between the vessel and the shield 17, and for flow downwardly in the space 181 between the shell and the inside of the ring 23. The spacers 175 are provided only at intervals around the ring 23 for flow of air down through the space 181.

The furnace 1 is provided with a lubricating system for the sets of bearings 97, 99, 101. A lubricating passage 119 is provided in the ring member 67 having one end communicating with the upper set of axial thrust bearings 97 and a fitting 121 is received in the ring member 67 in communication with the other end of the passage 119. Another passage 123 in the ring member 67 communicates between the passage 119 and the set of lower axial thrust bearings 99, and a lubricant supply tube 125 has one end connected with the fitting 121, its other end being connected to a suitable lubricant source (not shown).

In the operation of the furnace 1, power unit 57 drives gear 59 and thence pinion 61 to drive ring gear 103 to effect rotation of the vessel 3 within the tilt ring 23. The axially downward load or force of the vessel 3 is transmitted via sockets 113, pins 117 and the assembly of annular members 79, 81 and 83 to the upper set of axial thrust bearings 97 in journaling engagement between the bearing surface 91 of the upper annular member 81 and the upper bearing surface 75 provided on the ring flange 71. The axially downward force is transmitted through the annular ring member 67 and the machine screws 69 to the main ring 23, and, in this manner, the vessel 3 is not only vertically supported in the ring 23 but also freely rotatable therein. Any upwardly directed axial forces which may be imparted to the vessel 3 during rotation and/or tilting thereof, as discussed hereinafter, are transmitted via sockets 113, pins 117, annular members 79 and 83, and the lower set of axial thrust bearings 99 to the member 67 and ring 23. It may be observed that when the vessel is rotating with its axis inclined to vertical, its center of gravity is below the ring 23, with the result that on the high side of the furnace there are downwardly directed axial forces, and on the low side there are upwardly directed axial forces.

When it is desired to tilt the vessel 3 about its horizontal axis, gear 43 is rotated to tilt the ring 23 on the horizontal axis of its trunnions 25 and 27. Any radially directed force or load from the vessel 3 during the rotation and/or tilting thereof is transmitted via the sockets 113, pins 117 and annular members 79, 81 and 83 to the set of radial thrust bearings 101 and thence through the annular ring member 67 to the tilt ring 23.

With the axial and radial thrust bearing system as above described, the vessel 3 is adapted for operation in position with its axis at any angle to the horizontal,

and particularly at relatively high angles to the horizontal (c.g., close to vertical) for reducing the driving torque required to rotate the vessel without loss of agitation of the charge in the vessel, and for holding a greater charge in the vessel and reducing pollution. It will be observed that no movable parts such as would be apt to be subjected to materials spilling over when the vessel is being charged are required on the outside of the vessel. Maintenance, e.g., bearing replacement, may be carried out without inverting the vessel, thereby avoiding undue down time. The bearing system is also such that vibration of the vessel as it rotates is minimized, and the life of the refractory lining is thereby prolonged, and a thinner working lining may be used. It is also such that, on undue rise of temperature of the charge in the vessel 3 and consequent undue expansion of the vessel, the assembly 79, 81 and 83 opens up around member 67, so that the vessel may continue to spin freely.

FIG. 6 shows a modification of the drive for the vessel 3 which is particularly useful for vessels of high capacity (e.g., tons). This modified drive comprises a drive shaft 127 journaled in bearings as indicated at 129 on the horizontal tilt axis of the ring 23, this shaft being accommodated in the trunnion 25, the latter being made tubular for the purpose. A gear train generally designated 131 driven from shaft 127 drives the ring gear 103 and is movable with the ring 23 about its horizontal tilt axis. As shown, this train includes a bevel gear 133 on shaft 127 in mesh with a bevel gear 135 on a shaft 137 extending radially of the wheel 37. Shaft 137 drives a shaft 139 coaxial therewith via a clutch 141. A gear 143 on shaft 139 meshes with a gear 145 on a shaft 147 in a gear box 149 carried by the wheel, shaft 147 having a gear 151 thereon in mesh with the ring gear 103. The drive shaft 127 is driven in any suitable manner, and functions to drive the ring gear 103 and vessel 3 at any angle of the latter.

FIG. 7 illustrates a modification of the pin arrangement for supporting the vessel 3 in the ring 23, which may be preferred to that previously described. In this modification, sockets 191 are welded as indicated at 193 in openings 195 in the shell 13 of vessel 3 in line with the bosses 105 on the annular member 79. A tubular pin 197 is secured to each socket extending radially outwardly from the vessel 3 through a pair of spaced bushings 199 in the bore 109 of the respective boss 105. The pin has a tapered inner end 201 received in a tapered recess 203 of the socket, and is secured to the socket by means of a bolt 205 extending through the bore 207 of the pin threaded in a tapped hole 209 in the socket, and nuts 211 and 213 threaded on the outer end of the bolt. The pin is slidable in the bushings which may be formed of suitable bronze. The pin is provided with lubricant channels as indicated at 215, lubricant being supplied to the space 217 in the bore 109 between the bushings as indicated at 219 for supplying the channels. This arrangement enables lubrication despite the heat from the vessel 3.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructionswithout departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A furnace for metallurgical processing comprising a ring, means supporting said ring for the tilting thereof on a generally horizontal axis extending diametrically of said ring, a vessel for holding a charge to be processed, means mounting the vessel in said ring for rotation on an axis generally normal to the plane of said ring and extending generally centrally of said ring, and means for rotatably driving said vessel relative to said ring, characterized in that said mounting means comprises a first annular bearing means secured to said ring, a second annular bearing means secured to said vessel surrounding the latter, a set of radial thrust bearings interposed between said first and second annular bearing means, and at least one set of axial thrust bearings interposed between said first and second annular bearing means for bearing the load of said vessel.

2. A furnace as set forth in claim 1 further comprising a second set of axial thrust bearings interposed between said first and second annular bearing means for taking axial thrust in the opposite direction from the firstmentioned set of axial thrust bearings.

3. A furnace as set forth in claim 2 wherein said second annular bearing means comprises a ring gear constituting an element of said driving means.

4. A furnace as set forth in claim 1 wherein said first annular bearing means comprises an annular member secured to the bottom end portion of said ring and having an annular flange extending radially thereof, the edge of said flange constituting a peripheral bearing surface and a face of said flange constituting an annular bearing surface, said radial thrust bearings being interposed between said second annular bearing means and said peripheral bearing surface of said flange, and said axial thrust bearings being interposed between said second annular bearing means and said annular bearing surface.

5. A furnace as set forth in claim 4 wherein the other face of said flange constitutes a second annular bearing surface opposite the first annular bearing surface, and having a second set of axial thrust bearings interposed between said second annular bearing surface and said second annular bearing means for taking axial thrust in the opposite direction from said first-mentioned set of axial thrust bearings.

6. A furnace as set forth in claim 4 wherein said second annular bearing means comprises second and third interconnected annular members, said second member being disposed radially outwardly of said peripheral bearing surface and said set of radial thrust bearings being interposed between said peripheral bearing surface and said second annular member, a second annular flange extending radially inwardly from said second annular member between the bottom end portion of said ring and said annular bearing surface, said set of axial thrust bearings being journaled between said annular bearing surface and said second flange, means connecting said third member with said vessel, and one of said second and third members including a ring gear constituting an element of said driving means.

7. A furnace as set forth in claim 5 wherein said second annular bearing means comprises second, third and fourth interconnected annular members, said second member being disposed radially outwardly of said peripheral bearing surface, said set of radial thrust bearings being interposed between said peripheral bearing surface and said second member, a second annular flange on said second member extending radially inwardly therefrom between the bottom end portion of said ring and said first annular bearing surface, said first-mentioned set of axial thrust bearings being interposed between said second flange and said first annular bearing surface, a third annular flange on said third member extending radially inwardly therefrom below said second annular bearing surface, said second set of axial thrust bearings being interposed between said third flange and said second annular bearing surface,

means connecting said fourth member with said vessel,

and one of said second, third and fourth members including a ring gear constituting an element of said driving means.

8. A furnace as set forth in claim 2 comprising at least one pair of opposed annular bearing surfaces on said first and second bearing means, said set of axial thrust bearings being interposed between said one bearing surface pair, another pair of opposed annular bearing surfaces defined between said first and second bearing means and radially spaced from said one bearing surface pair, said set of radial thrust bearings being interposed between said other bearing surface pair.

9. A furnace as set forth in claim 2 comprising first and second pairs of opposed annular bearing surfaces defined on said first and second bearing means in axially spaced relation, a third pair of opposed bearing surfaces defined on said first and second bearing means between said first and second bearing surface pairs and radially spaced therefrom, respectively, said firstmentioned and second sets of axial thrust bearings being respectively interposed between said first and second bearing surface pairs and said set of radial thrust bearings being interposed between said third bearing surface pair.

10. A furnace as set forth in claim 1 comprising means connecting said second bearing means in supporting and driving relation with said vessel including means for accommodating thermal expansion of said vessel. 7

11. A furnace as set forth in claim 10 wherein said expansion-accommodating means comprises pins extending radially from one of said second bearing means and the vessel and sockets on the other of said second bearing means and the vessel slidably receiving the pins.

12. A furnace as set forth in claim 11 wherein the pins extend radially inwardly from the second bearing means and the sockets are on the outside of said vessel.

13. A furnace as set forth in claim 10, comprising a plurality of outboard bores in said second bearing means substantially radially of said generally normal axis, means secured to said vessel and defining a plurality of inboard bores spaced from and aligned with said outboard bores, and a plurality of connecting pins received in said bores, said connecting pins effecting concerted rotation of said vessel with said second bearing means and accommodating thermal expansion of said vessel. I

14. A furnace as set forth in claim 10, comprising a plurality of bores in said second bearing means and extending substantially radially of the generally normal axis, a plurality of sockets on said vessel aligned with said bores, and a plurality of pins received in said aligned bores and sockets, said pins being secured in said bores and extending into said sockets with a sliding fit in the latter.

15. A furnace for metallurgical processing comprising a ring, means supporting said ring for tilting of said ring on a horizontal axis extending diametrically of said ring, a vessel for holding a charge to be processed, means mounting said vessel in said ring for rotation on an axis generally normal to the plane of said ring and extending generally centrally thereof, means for rotating said vessel in said ring, characterized in that said mounting means comprises a first annular member secured to the bottom of said ring and depending therefrom and having an annular flange extending substantially radially outwardly thereof with respect to said generally normal axis, a peripheral edge on said flange defining a first bearing surface, second and third oppositely facing annular bearing surfaces on said flange, a second annular member on the outside of said first member and including fourth and fifth bearing surfaces spaced from and opposite to said first and second bearing surfaces, respectively, a set of radial thrust bearings interposed between said first and fourth bearing surfaces, a first set of axial thrust bearings interposed between said second and fifth bearing surfaces, at third annular member engaged with said second member and having a sixth bearing surface thereon spaced from and opposite to said third bearing surface, a second set of axial thrust bearings interposed between said third and sixth bearing surfaces, a fourth annular member engaged with said third member, a plurality of bores in said fourth member extending substantially radially of said generally normal axis, a plurality of sockets on said vessel axially aligned with said bores, a plurality of pins received in said aligned bores and sockets, said pins being secured in said bores and extending into said sockets with a sliding fit in the latter and one of said second, third and fourth members also defining a gear which constitutes an element of said rotating means.

16. A furnace for metallurgical processing comprising a ring, means supporting said ring for the tilting thereof on a horizontal axis extending diametrically of said tilting ring, a ring gear carried by said tilting ring for rotation relative to said tilting ring at one face of the tilting ring on an axis generally normal to the plane of said tilting ring and extending generally centrally of said tilting ring, radial and axial thrust bearings for the 10 7 ring gear, means for driving the ring gear, a vessel for holding a charge to be processed, and means mounting said vessel within the ring gear for rotation of the vessel with the ring gear and also accommodating relative expansive movement therebetween resulting from heat generated in said vessel.

17. A furnace as set forth in claim 16 wherein said mounting means comprises a plurality of pins respectively slidable with respect to at least one of said ring gear and vessel to accommodate the expansive movement.

18. A furnace as set forth in claim 16 wherein said mounting means comprises pins extending radially from one of said ring gear and said vessel and sockets on the other of said ring gear and said vessel in which said pins are slidably received.

19. A furnace as set forth in claim 18 wherein said pins extend radially inwardly from said ring gear and the sockets are on the outside of said vessel.

20. A furnace as set forth in claim 18 wherein said pins extend radially outwardly from the vessel and the sockets are in the ring gear.

21. A furnace as set forth in claim 1 wherein said second annular bearing means comprises a ring gear, and said driving means comprises a drive shaft on said horizontal axis, and a gear train driven from said drive shaft and driving said ring gear and movable with said ring about said horizontal axis.

22. A furnace as set forth in claim 10 wherein the pins are secured to the vessel and extend radially outwardly from the vessel through bores in said second bearing means, having a slidable fit in said bores.

23. A furnace as set forth in claim 22 having lubricating means for said bores. 

1. A furnace for metallurgical processing comprising a ring, means supporting said ring for the tilting thereof on a generally horizontal axis extending diametrically of said ring, a vessel for holding a charge to be processed, means mounting the vessel in said ring for rotation on an axis generally normal to the plane of said ring and extending generally centrally of said ring, and means for rotatably driving said vessel relative to said ring, characterized in that said mounting means comprises a first annular bearing means secured to said ring, a second annular bearing means secured to said vessel surrounding the latter, a set of radial thrust bearings interposed between said first and second annular bearing means, and at least one set of axial thrust bearings interposed between said first and second annular bearing means for bearing the load of said vessel.
 2. A furnace as set forth in claim 1 further comprising a second set of axial thrust bearings interposed between said first and second annular bearing means for taking axial thrust in the opposite direction from the first-mentioned set of axial thrust bearings.
 3. A furnace as set forth in claim 2 wherein said second annular bearing means comprises a ring gear constituting an element of said driving means.
 4. A furnace as set forth in claim 1 wherein said first annular bearing means comprises an annular member secured to the bottom end portion of said ring and having an annular flange extending radially thereof, the edge of said flange constituting a peripheral bearing surface and a face of said flange constituting an annular bearing surface, said radial thrust bearings being interposed between said second annular bearing means and said peripheral bearing surface of said flange, and said axial thrust bearings being interposed between said second annular bearing means and said annular bearing surface.
 5. A furnace as set forth in claim 4 wherein the other face of said flange constitutes a second annular bearing surface opposite the first annular bearing surface, and having a second set of axial thrust bearings interposed between said second annular bearing surface and said second annular bearing means for taking axial thrust in the opposite direction from said first-mentioned set of axial thrust bearings.
 6. A furnace as set forth in claim 4 wherein said second annular bearing means comprises second and thIrd interconnected annular members, said second member being disposed radially outwardly of said peripheral bearing surface and said set of radial thrust bearings being interposed between said peripheral bearing surface and said second annular member, a second annular flange extending radially inwardly from said second annular member between the bottom end portion of said ring and said annular bearing surface, said set of axial thrust bearings being journaled between said annular bearing surface and said second flange, means connecting said third member with said vessel, and one of said second and third members including a ring gear constituting an element of said driving means.
 7. A furnace as set forth in claim 5 wherein said second annular bearing means comprises second, third and fourth interconnected annular members, said second member being disposed radially outwardly of said peripheral bearing surface, said set of radial thrust bearings being interposed between said peripheral bearing surface and said second member, a second annular flange on said second member extending radially inwardly therefrom between the bottom end portion of said ring and said first annular bearing surface, said first-mentioned set of axial thrust bearings being interposed between said second flange and said first annular bearing surface, a third annular flange on said third member extending radially inwardly therefrom below said second annular bearing surface, said second set of axial thrust bearings being interposed between said third flange and said second annular bearing surface, means connecting said fourth member with said vessel, and one of said second, third and fourth members including a ring gear constituting an element of said driving means.
 8. A furnace as set forth in claim 2 comprising at least one pair of opposed annular bearing surfaces on said first and second bearing means, said set of axial thrust bearings being interposed between said one bearing surface pair, another pair of opposed annular bearing surfaces defined between said first and second bearing means and radially spaced from said one bearing surface pair, said set of radial thrust bearings being interposed between said other bearing surface pair.
 9. A furnace as set forth in claim 2 comprising first and second pairs of opposed annular bearing surfaces defined on said first and second bearing means in axially spaced relation, a third pair of opposed bearing surfaces defined on said first and second bearing means between said first and second bearing surface pairs and radially spaced therefrom, respectively, said first-mentioned and second sets of axial thrust bearings being respectively interposed between said first and second bearing surface pairs and said set of radial thrust bearings being interposed between said third bearing surface pair.
 10. A furnace as set forth in claim 1 comprising means connecting said second bearing means in supporting and driving relation with said vessel including means for accommodating thermal expansion of said vessel.
 11. A furnace as set forth in claim 10 wherein said expansion-accommodating means comprises pins extending radially from one of said second bearing means and the vessel and sockets on the other of said second bearing means and the vessel slidably receiving the pins.
 12. A furnace as set forth in claim 11 wherein the pins extend radially inwardly from the second bearing means and the sockets are on the outside of said vessel.
 13. A furnace as set forth in claim 10, comprising a plurality of outboard bores in said second bearing means substantially radially of said generally normal axis, means secured to said vessel and defining a plurality of inboard bores spaced from and aligned with said outboard bores, and a plurality of connecting pins received in said bores, said connecting pins effecting concerted rotation of said vessel with said second bearing means and accommodating thermal expansion of said vessel.
 14. A furnace as set forth in clAim 10, comprising a plurality of bores in said second bearing means and extending substantially radially of the generally normal axis, a plurality of sockets on said vessel aligned with said bores, and a plurality of pins received in said aligned bores and sockets, said pins being secured in said bores and extending into said sockets with a sliding fit in the latter.
 15. A furnace for metallurgical processing comprising a ring, means supporting said ring for tilting of said ring on a horizontal axis extending diametrically of said ring, a vessel for holding a charge to be processed, means mounting said vessel in said ring for rotation on an axis generally normal to the plane of said ring and extending generally centrally thereof, means for rotating said vessel in said ring, characterized in that said mounting means comprises a first annular member secured to the bottom of said ring and depending therefrom and having an annular flange extending substantially radially outwardly thereof with respect to said generally normal axis, a peripheral edge on said flange defining a first bearing surface, second and third oppositely facing annular bearing surfaces on said flange, a second annular member on the outside of said first member and including fourth and fifth bearing surfaces spaced from and opposite to said first and second bearing surfaces, respectively, a set of radial thrust bearings interposed between said first and fourth bearing surfaces, a first set of axial thrust bearings interposed between said second and fifth bearing surfaces, a third annular member engaged with said second member and having a sixth bearing surface thereon spaced from and opposite to said third bearing surface, a second set of axial thrust bearings interposed between said third and sixth bearing surfaces, a fourth annular member engaged with said third member, a plurality of bores in said fourth member extending substantially radially of said generally normal axis, a plurality of sockets on said vessel axially aligned with said bores, a plurality of pins received in said aligned bores and sockets, said pins being secured in said bores and extending into said sockets with a sliding fit in the latter and one of said second, third and fourth members also defining a gear which constitutes an element of said rotating means.
 16. A furnace for metallurgical processing comprising a ring, means supporting said ring for the tilting thereof on a horizontal axis extending diametrically of said tilting ring, a ring gear carried by said tilting ring for rotation relative to said tilting ring at one face of the tilting ring on an axis generally normal to the plane of said tilting ring and extending generally centrally of said tilting ring, radial and axial thrust bearings for the ring gear, means for driving the ring gear, a vessel for holding a charge to be processed, and means mounting said vessel within the ring gear for rotation of the vessel with the ring gear and also accommodating relative expansive movement therebetween resulting from heat generated in said vessel.
 17. A furnace as set forth in claim 16 wherein said mounting means comprises a plurality of pins respectively slidable with respect to at least one of said ring gear and vessel to accommodate the expansive movement.
 18. A furnace as set forth in claim 16 wherein said mounting means comprises pins extending radially from one of said ring gear and said vessel and sockets on the other of said ring gear and said vessel in which said pins are slidably received.
 19. A furnace as set forth in claim 18 wherein said pins extend radially inwardly from said ring gear and the sockets are on the outside of said vessel.
 20. A furnace as set forth in claim 18 wherein said pins extend radially outwardly from the vessel and the sockets are in the ring gear.
 21. A furnace as set forth in claim 1 wherein said second annular bearing means comprises a ring gear, and said driving means comprises a drive shaft on said horizontal axIs, and a gear train driven from said drive shaft and driving said ring gear and movable with said ring about said horizontal axis.
 22. A furnace as set forth in claim 10 wherein the pins are secured to the vessel and extend radially outwardly from the vessel through bores in said second bearing means, having a slidable fit in said bores.
 23. A furnace as set forth in claim 22 having lubricating means for said bores. 